High Internal-Phase Pickering Emulsions Stabilized by Xanthan Gum/Lysozyme Nanoparticles: Rheological and Microstructural Perspective

Preparation and Application of High Internal Phase Pickering Emulsion Gels Stabilized by Starch Nanocrystal/Tannic Acid Complex Particles

Herein, the starch nanocrystal/tannic acid (ST) complex particles, which were prepared based on the hydrogen bond between starch nanocrystal (SNC) and tannic acid (TA), were successfully used to stabilize the HIPPE gels. The optimal TA concentration of the ST complex particles resulted in better water dispersibility, surface wettability, and interfacial activity as compared to SNC. The hydrogen bond responsible for the formation of ST complex particles and subsequent stable emulsions was demonstrated by varying the pH and ionic strength of the aqueous phase. Notably, the HIPPE gels stabilized via the ST complex particles can maintain long-term stability for up to three months. The HIPPEs stabilized via the ST complex particles all displayed gel-like features and had smaller droplets and denser droplet networks than the SNC-stabilized HIPPEs. The rheological behavior of HIPPE gels stabilized via the ST complex particles can be readily changed by tuning the mass ratio of SNC and TA as well as pH. Finally, the prepared HIPPE gels used to effectively protect encapsulated β-carotene against high temperatures and ultraviolet radiation and its controllable release at room temperature were demonstrated. It is anticipated that the aforementioned findings will provide new perspectives on the preparation of Pickering emulsion for delivery systems.

Production and investigation of Pickering emulsion stabilised by casein-Qodume Shirazi (Alyssum homolocarpum) seed gum complex particles: gastrointestinal digestion

Recently, there has been growing research interests in designing Pickering emulsions. In this work, Alyssum homolocarpum seed gum (AHSG) and casein protein (CP) nanoparticles (NPs) fabricated as Pickering stabilizers. AHSG (0.0, 0.05, 0.10, and 0.15% (w/w))-CP (2% (w/w)) nanoparticles were fabricated and their properties were investigated (mean diameter, morphology, zeta potential, Fourier transform infra-red, and contact angle). Formation and stability of Pickering emulsion (Pes) stabilized by AHSG-CP NPs were monitored by mean diameter, rheological properties, and in vitro digestion. AHSG-CP Nps exhibited a small size (107.75 ± 0.42-201.52 ± 0.70 nm) and had wettability between 64.94 ± 3.44° and 70.92 ± 7.64°. The stability of PEs was greatly improved by 0.05AHSG-CP NPs, even after 30 days of storage, centrifugation, and in vitro digestion, owing to the reinforcement of particle structure at the oil/water interfaces.This study demonstrates that 0.05% (w/w) AHSG-CP NP showed the highest stability during storage and against gastrointestinal digestion which showed its suitability as a fat reducer emulsion structure.

Carrageenan-Based Pickering Emulsion Gels Stabilized by Xanthan Gum/Lysozyme Nanoparticle: Microstructure, Rheological, and Texture Perspective

In this study, Pickering emulsion gels were prepared by the self-gel method based on kappa carrageenan (kC). The effects of particle stabilizers and polysaccharide concentrations on the microstructure, rheological characteristics, and texture of Pickering emulsion gels stabilized by xanthan gum/lysozyme nanoparticles (XG/Ly NPs) with kC were discussed. The viscoelasticity of Pickering emulsion gels increased significantly with the increase of kC and XG/Ly NPs. The results of temperature sweep showed that the gel formation mainly depended on the kC addition. The XG/Ly NPs addition could accelerate the formation of Pickering emulsion gels and increase its melting temperature (T_melt), which is helpful to improve the thermal stability of emulsion gels. Cryo-scanning electron microscope (Cryo-SEM) images revealed that Pickering emulsion gel has a porous network structure, and the oil droplets were well wrapped in the pores. The hardness increased significantly with the increase of XG/Ly NPs and kC. In particular, the Pickering emulsion gel hardness was up to 2.9 Newton (N) when the concentration of kC and XG/Ly NPs were 2%. The results showed that self-gelling polysaccharides, such as kC, could construct and regulate the structure and characteristics of Pickering emulsion gel. This study provides theoretical support for potential new applications of emulsion gels as functional colloids and delivery systems in the food industry.

Characterization and antibacterial behavior of an edible konjac glucomannan/soluble black tea powder hybrid film with ultraviolet absorption

In this study, a KGM/SBTP film was prepared by a blending method using KGM and a soluble black tea film (SBTP) as substrates, and its hygroscopicity, thermal properties, light barrier properties, microstructure, and bacteriostatic properties were evaluated. The results confirmed that compared with the control group, with the increase in the SBTP content, the transmittance of the film in the ultraviolet region significantly reduced, and the water barrier property and thermal stability were improved. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) results indicated that the tea polyphenols interacted with the film substrate. SEM also showed that the structure of the KGM/SBTP films was smooth and flat, and all samples showed no fracture. In addition, the KGM/SBTP mixed membrane had obvious concentration-dependent antibacterial activity. When the concentration of SBTP was 0.9%, the inhibition zones against Staphylococcus aureus and Escherichia coli were 12.30 ± 0.20 mm and 12.05 ± 0.47 mm, respectively.

Pectin Stabilized Fish Gelatin Emulsions: Physical Stability, Rheological, and Interaction Properties

Pectin, a kind of natural polysaccharide, shows the attractive potential as a natural stabilizer for protein emulsion. The aim of this study is to investigate the effect of pectin on the physical stability, rheology, interface, and interaction properties of the fish gelatin (FG) emulsion, as pectin was utilized to improve the stability of FG, fish oil emulsion. During the study, when pH < 6, the FG-pectin emulsion displayed better storage stability and salinity tolerance. Analyzing the result, pectin could avoid phase separation at the freeze-thaw process and prevent the liquid-gel transition of FG emulsions during storage. On the other hand, when pH ≥ 6, the emulsion displayed high viscosity due to the complex flocculation and stratified during long-term storage. Electrostatic interactions, hydrophobic interactions, and hydrogen bonding of the FG-pectin complexes in the emulsion were all reduced. Overall, pectin improved the stability of FG emulsions through electrostatic repulsion, hydrophobic interactions, and steric hindrance.